body{
    padding:0;
    margin: 0;
    list-style: none;
    font-size: 12px;
    .wrapper{
        width:100vw; 
        height:100vh;
        background-color: rgba(0,0,0,0.2);
        padding-top: 60px;
        box-sizing: border-box;
        .song-img{
            width: 50%;
            height: 0;
            padding-top: 50%;/*父级宽度的50%*/
            position: relative;
            margin: 0  auto;
            border:1px solid #000;
            .img-wrapper{
                position: absolute;
                left:0;
                bottom: 0;
                top:0;
                right: 0;
                img{
                    width:100%;
                    height: 100%;
                }
            }
        }
    }
} 

